Using Microbiome Analysis to Assess the Impact of the Dreissenid Mussel Populations on the Ecology of Lake Mead

Project ID: 5385
Principal Investigator: Jacque Keele
Research Topic: Invasive Species
Funded Fiscal Years: 2016
Keywords: None

Research Question

Over the last few years the analysis of the microbiome (the microbial community) by next generation sequencing
(NGS) has enabled researchers to have a fuller understanding of microbial communities. Before the advent of NGS,
many microbes could not be analyzed because researchers could not culture the organisms in the laboratory. With
NGS researchers are able to inventory all of the organisms present in an environment (viruses, bacteria, protozoa,
ect). The use of microbiome analysis to assess the impact of an invasive organism, pollutant, or environmental
change needs to be explored so that researchers at Reclamation can come to understand, appreciate, and take
advantage of this technology.
For the last 10 years Lake Mead has been at the epicenter of the dreissenid (quagga) mussel infestation in the
western United States.Underlying the ecology of any body of water are the micro-organisms that inhabit the
system. The microbial community is important because of the roles it plays in decomposition, recycling, and as a
food source for higher invertebrates and vertebrates. Other researchers are using microbiome research to look at
the health and diversity of a wide range of systems including the human digestive track. Understanding the
microbiome can also help improve the understanding of the chemical recycling pathways (carbon and nitrogen for
example) and biogeographical processes that occur in bodies of water.The main goal of this project is to tie the
results of this molecular technique to the ecology of the system.
The NGS analysis will enable researchers to have a fuller understanding of the impact of the quagga mussel on
Lake Mead. In addition, microbiome samples will be taken from other sites along the lower Colorado River, Lake
Powell, and reservoirs in the Salt River Project system. This will allow us to compare the microbiome of these sites
to determine if there are organisms that are absent or over represented in waters where quagga mussels

Need and Benefit

Understanding the impact of the quagga mussels the microbiome of a body of water is important because it can
help determine the overall health of the system. Quagga mussels are filter feeders and thus consume microbes,
algae, and diatoms, and nutrients that are present in the water. The impact of a large quagga mussel population
on the microbiome of Lake Mead and other reservoirs has yet to be assessed.
The benefit of this research is that our understanding of impact of quagga mussels on the environment and
control methods will be increased. In this project we are planning on analyzing samples from Lake Mead and other
sites on the lower Colorado River system (infested with quagga mussel), Lake Powell (smaller population of quagga
mussel), and SRP (no known populations of QM) to determine which microorganisms are absent or present when
there is a quagga mussel infestation. All of these sites have been closely monitored for many years, so there is
environmental and chemical data that can be related to the microbiome of each site.
This research sets out to answer several questions that may provide significant insight into the health of a water
system in the presence of invasive species infestation. Some of these questions include: How fluid or stable is a
microbiome? Will each site have a unique microbiome or will there be common organisms that can indicate that
quagga mussels are present and/or absent from the water? There are many questions about the spread of quagga
mussels in western waters that remain unanswered. For example, why has the population not exploded
throughout western waters? What is limiting the population from expanding into new locations? A fuller picture
can be made by analyzing the microbiome and relating these results to data that has been already gathered.
Understanding the effects of the microbiome on mussel infestation is an area of research that has yet to be
applied to our understanding of how the mussels are spreading in western waters. For example, if certain
organisms are present only after an infestation, they might serve as indicators of a mussel invasion.
The use of next generation sequencing and microbiome research could be an important tool for researchers at
Reclamation. There are a many different projects where this technology could be used such as control method
development. For example, analysis of fish guts, dam drain and pipes, and the microbiome of water reuse
facilities all would be very interesting projects where this technology could be applied to improve control
technology. Understanding the interactions that occur in an environment between the microbiome and
environmental factors such as temperature, pH, and depth, is important to building a fuller picture of a body of

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Using Microbiome Analysis to Assess the Impact of the Dreissenid Mussel Populations on the Ecology of Lake Mead (final, PDF, 439KB)
By Jacque Keele
Publication completed on September 30, 2016

Next generation DNA sequencing (NGS) is allowing researchers to study and understand the ecology of the microbial communities from a wide range of locations and conditions. For this scooping project samples were collected from Lake Mead, NV and the Salton Sea, CA for microbial analysis. The DNA was extracted and sent for NGS analysis. The goal of this project was to plan and design a NGS study. Lake Mead was selected as one of the sites because of its large invasive Dreissenid mussel population. The Salton Sea was selected because of its unique chemistry and environment. Once the NGS analysis is complete a list of the microbial organisms present at each site will be compiled. The data collected in this scooping project will be used in future projects to understand how the microbiome is impacted by both the presence of invasive mussels and environmental changes.

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Last Updated: 6/22/20